Combined spark arrester and muffler for internal combustion engines



May 17, 1960 F. R. GILL 2,936,844 COMBINED SPARK ARRESTER AND MUFFLER FOR INTERNAL COMBUSTION ENGINES Filed Nov. 1a, 1955 INVENTOR. FRA/V/f R- 6/11 United States Patent i 2,936,844 COMBINED SPARK ARRESTER AND MUFFLER FOR INTERNAL COMBUSTION ENGINES Frank R. Gill, Sacramento, Calif. Application November 18, 1955, Serial No. 547,632

- 1 Claim. (Cl. 181-36) This invention relates to a spark arrester for internal combustion engines and particularly to a device of this kind whichis adapted to be mounted in the exhaust system thereof.

In devices of this kind, extreme fire hazards are likely to result from hot sparks escaping from the exhaust of these engines. When devices of this kind are used around areas in which aircraft are being serviced, for example, the presence of this hazard is increased.

It is an object of the present invention to provide a device of this kind which will prevent the escape of hot sparks.

It is a further object of this invention to provide a device of this kind which separates the gaseous and solid material emitted from these exhausts, allowing the cooler gases to escape while restraining and collecting the hotter solids which constitute the fire hazard.

A further object of this invention is to provide a safety device which separates the lighter gaseous material from heavier solid particles by centrifugal force.

Other objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawings in which:

Figure 1 is an end elevational view with the outer end surface cut away.

Figure 2 is a cross-sectional view of the device taken along the line 2-2 of Figure 1.

Figure 3 is a view taken along the line 3-3 of Figure 1 showing the trap in closed position.

Figure 4 is a view taken along the line 3-3 of Figure 1 showing the trap in discharge position; and

Figure 5 is a view taken along the line 5--5 of Figure 4.

As illustrated generally in Figures 1 and 2, my device consists of a spark arresting section and a mufiler section 11.

The spark arresting section 10 consists of a hollow casing portion and is provided with an inlet passage 12 which, as shown, is substantially in horizontal position, and through which exhaust gases and hot sparks are introduced into the casing 10. The casing 10 is provided with a trap portion 13 which is generally tubular in cross section, and preferably extends downwardly from the housing 10. The remote end of the trap portion 13 is provided with an end wall 14 in which there is an opening 16. A rotatable plate 17 which is pivotally connected to the end plate 14, as by means of a bolt 18, is likewise provided with an opening 19 which may be positioned in registry with the opening 16, as viewed in Figures 4 and 5, or may be positioned out of registry with the opening 16, as illustrated in Figure 3. The purpose of this device will more fully hereinafter be explained.

The casing 10 is composed generally of a pair of similarly shaped sections 21 and 22 which may be secured in any suitable manner. The section 21 is provided with an opening 23, but the similar portion of the section 22 is enclosed. An inwardly extending flange 24 provides ice an opening 26 which is substantially coaxial with the housings 10 and 11. The opening 23 accommodates the open end of a tube 27 which is provided with orifices 28. The housing 11, one end of which is secured to the shell or casing 10, is provided with an end member 29 having an exhaust port 31.

A baflle 32 is also mounted in the casing 10, and the bafile 32 is mounted generally as shown, i.e., in a generally downwardly deflecting position. The housing 10 forms in efiect a toroid. The opening 23 is generally positioned at the inner circumference of the toroid, while the inlet passage 12 and the trap portion 13 are positioned generally on the outer circumference of the toroid. The. combustion products emitted from the engine exhaust are introduced into the toroid from the passage 12, and are given a swirling or circular motion, and thus a continuous exhaust outlet is provided at the inner circumference of the path of travel of the exhaust gases through the opening 26 in the flange 24. The inlet passage 12 and the trap 13 both lie tangentially with respect to the outer circumference of the toroid and the circular outlet 26 is placed at the inner circumference of the toroid.

The gases which are lighter are allowed to escape at the center of the system. The products of combustion enter the system from a tangential direction and the separation of light and heavy particles is elfected by centrifugal force, and the heavier particles leave the system in the natural tangential direction of the trap 13. It will be recalled that the baffle 32 is positioned in a generally downwardly deflecting manner so that the heavier particles which engage the bafile 32 are directed downwardly into the trap 13. Solid particles dropping out and reaching the trap 13 will be retained thereby when the openings 16 and 19 are not in registry, as indicated in Figure 3, but may be removed therefrom when the openings 16 and 19 are in registry or in the position illustrated in Figures 4 and 5.

As the gases are vented from the toroid 10 through the openings 26 and 23, they pass through the openings 28, the tubular member 27, into the enlarged chamber 11, and into the atmosphere through the outlet passage 31. In this manner the exhaust is muflled.

Operation of the device may be described as follows: Solid and gaseous products of combustion emitted from the exhaust and engine are introduced through the passage 12 and are deflected by the toroid formed by the casing 10 in a circular swirl. Their path of travel is indicated by the arrows in Figure 2. A portion of the gases escape immediately through the center opening 26. The flange 24 however, baffies back most of the hot solid portions or sparks whose escape would constitute the fire hazard. Whatever portion of gaseousmaterial does not at first escape through the opening 26 encounters the baffie 32 where it is deflected back and travels again through the system. Its forceful entrance into the trap may be thus retarded, but the solid particles which engage the baffle 32 will drop out and fall into the trap 13.

It will be apparent from the foregoing that I have provided a combined spark arrester and muffler which fulfills the objects outlined earlier in this specification.

I claim:

In a combined spark arrester and mufiler for attachment to the exhaust pipe of an engine, a hollow casing of substantially toroidal form, the casing consisting of a pair of bell-shaped members, the axis of the toroidal casing being in a substantially horizontal plane, said casing being formed with a tangentially disposed inlet spaced substantially equidistant from the opposite sides of the casing, the inlet being adapted to be connected to said exhaust pipe whereby exhaust fumes entering the casing are given a swirling motion about the inner periphery of the casing,

a trap mounted on said casing, said casing being formed with a tangentially disposed opening spaced from said inlet and in communication with said trap whereby dirt particles and sparks in said exhaust fumes are received by said trap, a flange disposed within said casing adjacent. one side of said casing, said flange defining a central opening, the side of said casing adjacent-said flange being formed with a central opening and communicating with the openingdefined by said flange, a bafile disposed in said casing between said flange and the side of said casing farthest removed from said flange, a substantial portion of said baffie overlying the opening communicating with said trap, said bafile being spaced from the inner periphery of said casing to permit the gas fumes to pass therebetween, a substantially cylindrical muffier housing fixed to the side of the casing having a central opening therein and having an axis coincident with the axis of said casing, the housing being formed with a discharge opening, and an annular tubular member disposed within said housing and having one end in communication with the central opening in said casing to receive exhaust fumes from the casing after they have been swirled in the casing.

References Cited in the file of this patent UNITED STATES PATENTS Re. 19,942 Alexander Apr. 28, 1936 1,304,096 Redeker May 20, 1919 1,344,367 Wickersham June 22, 1920 1,591,677 Garner July 6, 1926 1,811,762 Schnell June 23, 1931 2,075,264 Bourne Mar. 30, 1937 2,170,704 Bourne Aug. 22, 1939 2,265,343 Bourne Dec. 9, 1941 2,888,096 Evans May 26, 1959 

